Apparatus for the production of powdered material



c. A. BULKELEY APPARATUS FOR THE PRODUCTION OF POWERED MATERIAL June 171924.

Original Filed Dec. 9, 1919 Patented June 1,7,1924.

snare HST'EV CLAUDE A. BULKELEY, OF WILMINGTON, DELAWARE, A$SI GNOBTQ E.I. DU FONT DE nnnronns & comrANY, or WILMINGTON, DELAWARE, A co WARE.

arraaarus non rnn rnonnc'rron or rownnnni) Mara @BATION F DELA-Applicationv filed December 9, 1919, Serial No. 343,467. RenewedNovember 22, 1923.

To all whom it may concern:

Be it known that l, CLAUDE A. BULKE- LEY, a citizen of the UnitedStates, and a resident of \Vilmington, inthe county of New Castle andState of Delaware, have mvented a certain new and useful Apparatus forthe Production of Powdered Material,

of which the following is a specification.

This invention relates to apparatus for the production of finelypowdered material, and since the illustrated apparatus finds particularapplication in the art of produc ing bronze powder, although it is notrestricted thereto, 1 describe it with more particular reference to thatart.

In the making of bronze powder by hammering the metal to reduce it tosmall particles it is important that the finished fine powder beaccurately separated from the unfinished larger particles, otherwise thepowder will have its quality impaired by the presence of particles toolarge to be properly included therein. Also, it is important that whenany particles have been reduced. to desired slze they be removed fromthe action of the reducing machine, otherwise suc particles ing theirbrilliancy, instead of remaining fiat, flake-like and brilliant. Various"apparatus have heretofore been proposed for the grinding and separationof certain materials but such apparatus are not well adapted to theproduction of bronze powder, for they do not separate the particles withsuffic ent accuracy, and

have not suitable provisions for avoiding over-treatment. For example,it has been proposed to assemble together agrinding machine discharginginto a hopper below terial leave the machine after it should and so isover-treated, but also much material leaves before it should and so-has"-to be rehandled and returned to the machine. Another difficult isthat since the screen i screen.

become 1 over-' treated, thereby becoming granular and los-' is in theseparator and an operative part thereof, it is subjected to forcestending to forcibly drive the particles through the screen, e. g.,forces causing the separation, whereby the accuracy of the screening isdestroyed, resulting in the presence in the supposedly fine powder of alarge number of coarse particles driven through the Moreover, the screenof the apparatus, being stationary, has not that high degree of abilityto screen the powdered material accurately which it is desirable to havepresent in a screening device used for screening bronze powder. Ihavedevised an apparatus by the use of which bronze powder of desiredfineness and uniformity, and having its particles flat, flake-like andbrilliant, can be conveniently produced.

An object-"of my invention isto provide" an apparatus for the productionof pow-. dered material which apparatus shall provide for the removal ofthe material from the reducing machine upon the material reaching thedesired degree of fineness, thereby avoiding over-treatment, and alsoprovide for the accurate separation of the finished material from theunfinished.

To this end, and also to improve gener Figure 2 is a sectional view ofthe reducing machine included in the apparatus illustrated in Figure 1;

=Figure 3 is substantially a longitudinal sectional view of the rotaryscreen and adjacent parts, included in the apparatus illus- -tra ted 1nFigure 1, and

Figure 4 is a cross-sectional view substantially on the line. 4- ofFigure 3, but with the partition wall of the casing omitted.

Referring now to the drawings, the illustrated apparatus comprises'areducing machine 1, in the character of a stamping mill, acycloneseparator 2, a rotary, horizontal, poly onal' screen 3, and a fan orblower 4. in air tight system of pipes 5, 6 and 7 provides forcirculation of air from the mill 1, through the fan 4, to the separator2, and back to the mill. A pipe 8 is provided for conducting to therotary screen through the meshes of the screen; a pipe .tion -may beselectedfor each, independ till 10 returns unfinished material from thedischarge end of' the screen to the ma chine, and the pipe 11, connectedwith the' pipe 10, return's'to themachine such mate rial as may bychance fail to enter, or to remain in, the entrance end of the screen.The machine, fan and screen are driven from any suitable source orsources of power (not shown), the drives. being independentlycontrollable, as by changing the pulley sizes, so that the desired speedof operaentlyoi the others,

In the operation of the apparatus, coarse bronze powder is supplied atintervals to the hopper 12 on an extension 10* of the pipe 10 and isreduced by series of hammers as 13 and 1d. The particles as they becomesuficiently reduced, are carried up the pipe 5' by the air current,separated from the air by the separator, and discharged into the screen;the air returning from the separator to the machine through the pipe 7.Finishcdpowder is discharged from the screen through the piped),unfinished material is discharged through the pipe 10 back to themachine, and spilled material is discharged through the pipes 11 and 10,

back to the machine, Thus the action is continuous, coarse materialbeing sup lied as required to the hopper 12 and finished materialremoved at the lower end of the pipe-9.

1 As shown more particularly in Figure 2, the pipes 5 and 7 communicatewith the reducing chamber 15 of the. machine 1 above the anv'ils 16, 16,whereby the material being reduced is not directly discharged into thepipe 5, that is, is not discharged by gravity, for example, and the airentering at the pipe 7 does not blow up throughthe charge C, but,instead, blows over it. With this arrangement, with the hammers, as 13and 1d, keeping the charge in a constant state of agitation the smaller.parti cles float in the air current. The strength of the air current isso regulated that these finer lighter particles are carried upward tothe screen, while the coarser heavier particles are left behind forfurther treatment, and an initial separation of the particles is made.The finer particles are removed from the machine as soon as they aresuficiently reduced and therefore are not subjected to over-treatmentthat would tend to render them granularinstead of fiat, fiakelilre andbrilliant For practical reasons, It prefer not to attempt to make theseparation at the reducing machine absolutely enact, but, rather, use anair current sntliciently strong to carry away ea ers a certain amountofslightly' oversize particles, and I make the final separat on at thescreen 3.

As previously pointed out the screen is separate and distinct from thecycloneseparator 2. With the screen thus separate and distinct from theseparator, there is no forcible driving of oversize particles throughthe screen-an action that would of course introduce inaccuracies intothe screening. Also, by having the screen separate from the separator 11am able to use as fine and delicate a screen as l desire, not having toconsiderwhat might be the efi'ect on such a screen were it to be placedin the separator to be subjected to swirling particles and so forth.Again, by having thescreen separate from the separator 11 am enabled touse a rotary screen, which I could not feasibly do were thescreen'within the separator; and so can get a more accurate separationthan would be conveniently possible with a stationary screen;

It will be noted also that, since the air current is created, not by theaction of the reducing machine, but by an independent element, the 1fan, the stren h of the current can beregulated as desired, withoutregard to what the desired speed of the machine may be, Also, theetl'ect of the screen is determinable. by its speed of rotation and soiorth and is not dependent upon the strength of theair current or forcesacting within the separator, and, so,

can be regulated to exactly meet desired conditions; and the air currentcan. be regulated withouthaving to consider its efiect at the screen,Thus the effect of each element of the apparatus can be accuratelyregulated, independently of the others, to

secure the best results.

The details ofthe various elements of the apparatus may be of anysuitable or preferred character. As here illustrated the reducingmachine is of the type commonly called a sixteener machine its series ofhammers, as 13, being driven by cams, 17, carried by a shaft 18; and itsseries of hammers, as 1 1, being driven by cams, as 19, carried by ashaft 20. Qne shaft, as 18, is driven by the belt pulley 21, and themotion is transmitted by gearing 22 22'" to the shaft 20, The fan is oithe usual type driven by the belt pulley 23 from, say, an electric motor(not shown).

leaving at 25; The screen 3 comprises 1 frame composed of theelements 26which are carried by, the spider 27 and the end plate 28 mounted torotate with the shaft 29 driven by the pulley 30. @n the elements 26 ispreferably carried Zllil mesh,

lllll ill) : claim eaders silk bolting cloth. The receiving end of thescreen is open, while the end plate 28 closes the discharge and exceptfor exit apertures, 31. Desirably the pipe 5 -is,

as shown, of relatively large diameter adjacent the machine 1 and ofrelatively small diameter along'the major portion of its length.Desirably, too, the lower portion of the pipe 7 is of smaller diameterthan the portion thereof adjacent the separator. Conveniently a portion7 of the pipe 7 may be flexible, as of canvas, to facilitate the openingof the door 1 of themachine, for inspection or any desired purpose. Itwill be understood that proper brackets, supports, and so forth, for thevarious 'elements of the apparatus are provided, but to avoid confusionno attempt is made to illustrate such parts. Also, although forsimplicity in the drawings but one entrance pipe 7 and one exit pipe 5,and but one separ'ator, one screen, etc, have been shown, it will beunderstood that asmany entrance and exit pipes spaced along the chamber15, and as many separators, screens, etc., can be used as are desirablefor the objects sought.

Although I have described my invention with more particular reference tothe illustrated embodiment, it will. be understood that Iydo notrestrict it thereto, for it may be embodied in many other and differentapparatus. I

Having thus described my invention, '1

1. In an apparatus'for the production of powder, in combination, areducing machine aving a chamber for holding the material to be actedon, and means in. said chamber for acting on the material, conductorsproviding an air circuit with said chamber included therein, means formovin air through said circuit, a separator in luded in said circuit,vand a screen located without said circuit and operatively distinct fromthe separator, said separator and screenbeing arranged for the dischargeof material from the separator to the screen.

2. In an apparatus for the production of powder, in combination, areducing machine having a chamber for holding the material to be actedon, and'located to support such material upon the bottom thereof, andmeans in said chamber for acting on the material, conductors providingan air circuit with said chamber included therein, with the'entranceconductor and the exit conductor communicating therewith above thebottom thereof, thereby to provide that the air circulating through saidchamber shall pass across the material, means for moving air throughsaid circuit, a separator included insaid circuit, and a screen, saidseparator and screen being arranged for the discharge of material fromthe separator to the screen,

3. In an apparatus for the production of powder in combination, areducing machine aving a chamber for holding the material to beactedfon, andlocated to support such material upon the bottom thereof,and means in said chamber for actingon the material, conductorsproviding an air circuit with said chamber included therein, with theentrance conductor and the exit conductor communicating therewith abovethe bottomthereof, thereby to provide that the air circulating throughsaid chamber shall pass across the material I means for moving airthrough said circuit, a separator included in said circuit, and a screenlocated without said circuit and operatively distinct from theseparator, said separator and screen being arranged for the dischargeofmaterial from the separator to the screen.

' 4. In an apparatus for the production of 'throuh said circuit, aseparator included 1n sai circuit, and a screen located without" andagitating the material, conductors providing an air circuit with saidchamber included therein, with the entrance conductor and the exitconductor to and from said chamber communicating therewith above thebottom thereof, means for moving air through said circuit, a separatorincluded in said circuit, and a screen, said screen being.

operatively distinct from said separator,

said separator and screen being arranged for the discharge of materialfrom one to the other,

6. In an ap aratus for the production of terial, said chamber havinganvil means at its bottom, said mill also embodying stamp.-

ing means operative in said chamber] and cooperating with said anvilmeans to reduce the materlal, conductors providin an air circuit withsaid chamber include therein with the entrance conductor and the exitlit!) conductor to and from said chamberv communicating therewith abovesaid anvil means with said stamping means substantially in the line ofthe air current, driven means for moving air through said circuit, aseparator included in said circuit, a screen, a conductor from saidseparator to said screen, a conductor from said screen to said mill forreturning unfinished powder there to, a conductor for dischargingfinished gowder from the screen, and means for c riving said mill andsaid moving means.

7. In an apparatus for the production of powder, in combination, adriven stamping mill embodying a chamber for material, said chamberhaving anvil means at its bottom, said mill also embodying stampingmeans operative in said chamber and cooperative with said anvil means toreduce neeaere the material, conductors providing an air circuit withsaid chamber included therein With the entrance conductor and the exitconductor to and from said chamber communicating therewith above saidanvil means with said stamping means substantially in the line of theair current, driven means for moving air through Saidcircuit, aseparator included in said circuit, a driven rotaryscreen, a conductorfrom said se arator to said screen, a conductor irom sai screen to saidmill-for returning unfinished oWder thereto, a conductor for dischargingfinished mowder from the screen, and means Whereoy said driven mill,moving means, and screen can be driven each at a speed. independent Orthat of the others.

In testimony whereof I affix my signature.

CLAUDE A. BULKELEY.

